Tsukumogami

A tsukumogami (付喪神) is a type of youkai produced from a tool or object inhabited by one of the eight million gods. In Japanese legend, all types of tsukumogami gain life and sentience on the 100th anniversary of their creation, and can range from harmless and friendly beings to horrifying vengeful spirits, depending on how they were treated and used. It is also said that modern electric items cannot become tsukumogami. It is unclear on how tsukumogami are treated in the Len'en Project. The only known example thus far is Mitsumo.